The development of asymmetric conjugate addition reactions for carbon-carbon bond formation remains an important challenge in organic synthesis.1,2 Much recent work has focused on organocatalytic Michael addition of carbonyl compounds to nitroalkenes.3-5 Among these reactions, Michael addition of aldehydes to nitroalkenes is of particular interest because of the valuable synthetic intermediates that are generated.4 β-Aryl nitroalkenes have been the most common Michael acceptors. These Michael reactions provide α,β-disubstituted-γ-nitrobutyl aldehydes. Access to adducts that bear only a single substituent adjacent to a carbonyl are of interest because they can be readily converted to γ2-amino acids. γ2-Amino acids represent potential building blocks for γ-peptide6 and heterogeneous backbone foldamers.7 Derivatives of the neurotransmitter γ-amino butyric acid (GABA)8 are of potential biomedical utility, illustrated by the use of Pregabalin and Baclofen to treat neurological disorders.9 
Preparation of enantiomerically pure γ-amino acids is challenging and this synthetic hurdle has limited the study of γ-peptide foldamers to date. A variety of routes to enantioenriched γ2-amino acids have been described,10 but these approaches often involve specialized chiral auxiliaries and may not be ideal for preparing multigram quantities of protected γ2-amino acids bearing diverse side chain functionality, which is necessary for foldamer research.
Accordingly, new methods for the synthesis of γ2-amino acids, especially enantioselective methods, would significantly aid the preparation and study of γ-peptide and heterogeneous backbone foldamers. Such methods would also help to facilitate evaluation of their potential biomedical uses. Therefore, new synthetic methods for the preparation of versatile adducts that can be converted to converted to γ2-amino acids would be of significant value to the research community.